Question

Find the mean of the following marks (out of 10) obtained by 20 students:

4, 6, 5, 9, 3, 2, 7, 7, 6, 5, 4, 9, 10, 10, 3, 4, 7, 6, 9, 9​

Answer 1

Step-by-step explanation:

52×(169+26x)=(x+13)^2

52×(169+26x)=x^2+169+26x

8788+1352x=x^2+169+26x

x^2-1326x-8619=0